I'm not sure how you don't get any index out-of-bounds errors because you're trying to index an array from 0 to 99 where the array is much much smaller than 100 (in your case 4 or 5 depending on which function call you're using).
You can actually determine the size of the provided array by using the sizeof directive as the default for a "length" parameter:
PHP Code:
myFunction(myArray[], len = sizeof myArray)
{
server_print("Array Size: %d", len)
}
where
PHP Code:
myFunction({1,3,5})
myFunction({1})
myFunction({2,34,3.34,3.0,34.0,34,0.0})
results in:
Code:
Array Size: 3
Array Size: 1
Array Size: 7